v18: Bug with data counting in firewall rules?

Hi cryptochrome, 

Could you please share the screenshot of the firewall rule that shows data in and out counters? I will verify if it should be like that or not and update you.

Thanks,

Hi cryptochrome, 

Could you please share the screenshot of the firewall rule that shows data in and out counters? I will verify if it should be like that or not and update you.

Thanks,

Sure, here you go:

Firewall Rule:

Corresponding NAT rule:

Firewall Rule Details:

Note that this is just one example. I am seeing the same "reversed" counter on other incoming rules. 

How do you count the data? If someone on the internet initiates the connection and transfers a lot of data, does that count as incoming or outgoing?

LuCar Toni said:

PS: If Sophos change those values, they would not make any sense to me.

Obviously.

And that's the whole problem here. You still don't understand the issue. And you refuse to even consider that something you don't understand ("make any sense to me") could actually be right.

I guess ignorance is bliss.

LuCar Toni said:

 

Sophos could simply remove IN/OUT Terms to meet other vendors. 

Since you edited your post while I was typing my response, here is my reply to the additions you made to it:

LuCar Toni said:

 

So you are agree with me, there is no Bug nor inconsistency in the whole process? 

God, this is painful. No, I do not agree with you. Because you refuse to understand the issue. I have repeatedly stated that there is in fact an inconsistency, because the data counting actually works fine on outgoing, SNAT/MASQ traffic. It works differently on incoming DNAT traffic. So there is at least an inconsistency. Whether that inconsistency should be labeled as a bug is not for me to decide (although I would definitely see it as one).  

LuCar Toni said:

The only point, which you want to have, is to change/switch both values for A/all firewall rules, correct? 

If you would change it for all Rules, maybe other firewall rules could be not logically anymore. 

No :-/ Not correct. I do not want values changed for all firewall rules. Only for those where the indication of traffic direction is actually wrong (from what I can tell, that is only relevant to incoming DNAT traffic). 

But you're not listening, so whatever. 

LuCar Toni said:

So you are agree with me, there is no Bug nor inconsistency in the whole process? 

I understand what cryptochrome is trying to explain to you, but in my opinion, this isn't a bug.

I don't even care about the data counting in the rules, every other NGFW vendor I've used never showed the data counting as XG shows, they always showed in the Rule "Hit Counter". At the same time showing the first time the Rule has been used, and the last time It has been used. Which is much better than showing just the amount of data transferred over that rule in XG right now.

If you wanted to see the traffic bandwidth being transferred over a rule, you would use the Logs or the Reporting system of the appliance. The only problem of doing this in XG, is because the current logs & reporting system is bad compared to the competition.

Thanks!

Please moderate with the terms. If someone here can open a ticket with the support to investigate can really help.

For reporting, I do not like them compared to competition and to UTM 9 either.

I have the doubt that this in/out issue generates false reports too.

As feature, I am waiting reports per interface where you can start from interface and drill down to services, applications, users and so on. This is one of the most reporting I am using on UTM and on other products.

Thanks

Maybe i did a bad Job in explaining the underlying issue.

Will try it again, because i understand, why this is causing an issue to people, but to resolve this, it is not quite easy.

You have different perspectives for Firewall logging. You can perform it on different level.

Interface Level (LAN or WAN Interface). Connection based (Client to Server, how much Data is processed - No IN/OUT).  

Logging on the Interface, you have always the perspective IN/OUT. A Firewall always(usually) interact with two Interfaces in a basic communication. So you have two IN/OUT for the same Connection. You have the Destination Interface and the Source Interface. 

Logging on the Connection, you would have Data send by A and by B. There is no UP/DOWN, only Bytes from A / Bytes from B. Or Bytes from Client, Bytes from Server.   

Lets say, you are establish a connection between LAN Client and WAN Server. You could start to log the traffic now based on the Traffic from the WAN Interface or LAN interface. 

From the LAN Interface, the Connection could be Logged as IN/OUT.

From the WAN Interface, the same Connection, IN/OUT would be switched. 

From the Connection based, you would have Bytes by LAN Client and Bytes by WAN Server. 

Lets now look at XG. The design for years was to take the traffic from the "Destination Interface" perspective. 

That made sense for the use Case of LAN to WAN. From the WAN interface perspective, Servers are sending date (IN) and Clients are sending data (OUT). 

For DNAT, this could be an issue. The Destination Interface is DMZ. So the Client in WAN is sending Traffic (OUT), the Server in DMZ is Sending traffic (IN).

If you leave the LAN/WAN concept and look at LAN to DMZ, you would have a certain expectation: DMZ Interface as Logging Interface: Because most likely your Client (LAN) is talking to a Server (DMZ).

But this get more and more complicated if you take the bigger picture. You have LAN to LAN. What are you logging? DMZ to DMZ? (two Interfaces in the same Zone). You have your own created Zone? 

Should XG automatically figure out which Interface is used and switching the logging based on the connection Destination? Could be "misleading" as well. I am not able to figure out a solution but to give the administrator the possibility to choose at their own, which way around the logging should be done. 

What would be the solution? cryptochrome Maybe you could give us some insights, how other vendors do this? Because as far as i know, they most likely only log the Connection (How much traffic is proceed with this rule) without any IN/OUT indicator. That is my finding at the moment. Please consider the bigger picture in resolving this issue. 

*Edit* Forget one Use Case: Maybe use the WAN interface, then switch between IN/OUT because it is uploaded? But this would not work for VPN, MPLS etc. Also no solution. 

As Prism explained, most NGFW are only using the Connection logging for their Firewall rules (which would be only sent by A / B, not IN/OUT). 

Hope this is clear. If not, we can continue this Discussion via PM, if you want. Happy to explain this in more detail, why there is no inconsistency in the current Solution. 

PS: Reports are generated based on the connection level. 

Hello cryptochrome,

I fully agree with you! Your conclusion is perfectly logical and correct. However, there are considerably more illogical things in XG and no one is doing anything about them. They even add others such as defining DNAT rules. This is absolutely monstrous! And how developers solved the illogical creation of DNAT rules:

- added Server access assistant (DNAT) which automatically creates loopback and reflexive rules (I never needed to define them in my life, probably some Cyberoam paranoia)
- as public IP addresses offer IP addresses from the internal network, is it really a big problem to select only IP addresses defined in the WAN or DMZ zone, really?
- it is not possible to define the network service to which traffic is to be redirected under this unique tool. So you need to stop creating the DNAT rule, define the needed service and start over. I guess I didn't mention that it is not possible to use groups of services, but who would need it, right?
- and what a surprise, as the source network we are offered the whole world, all physical ports, internal networks, DNS domains, DNS hosts but it's really special, zones are not available. Well, who needs it, right?
- and in the final you will see an overview of all the horrors and what a surprise it is not possible to save the rule as inactive! What a surprise when a firewall rule can be saved as inactive ?!

And the biggest surprise at the end, this is GA version !!!

Sorry, this post is absolutely unrelated to this thread, I just wanted to point out that illogicality is many times more across the XG Firewall.

Regards

alda

Luca, thanks for explaining again in detail. I fully understand how it works, and I completely understand where you see the problem:

From the LAN Interface, the Connection could be Logged as IN/OUT.
From the WAN Interface, the same Connection, IN/OUT would be switched. 
[...]
The design for years was to take the traffic from the "Destination Interface" perspective.

This is absolutely correct. Depending on perspective (external vs. internal), from a logical point of view, direction switches. And that's why taking the "destination interface" perspective just doesn't cut it. It leads to logic errors, as we have just established. 

Other firewall vendors solve this by letting the firewall know which networks are considered internal networks and which ones are considered external. On Checkpoint, for example, you explicitly define a network topology in the firewall config. You assign networks into different brackets (namely internal and DMZ, the rest it automatically considered external). Some other firewalls do this more simply by just using route lookups (anything that is not in the routing table, e.g. uses the default route, is considered external). Juniper uses a combination of zones and routes. 

Once it is determined whether the session initiator is external or internal, you can derive the correct "perspective", e.g. traffic direction.

If initiator is external, count like this:

Initiator sends data = INcoming
Initiator received data = OUTgoing

If initiator is internal, count like this:

Initiator sends data = OUTgoing
Initiator receives data = INcoming

Sophos XG already uses zones. It even has a designation for each zone. You could consider every zone designated with WAN role as external. Voila. 

Thanks for your suggestion.

What about other zones, which actually could be external (VPN Zone, MPLS Zones, Zones behind routing devices (For example Dark Fiber etc.))? You would consider them as external or Internal? Giving the administrator a option to decide about each zone could be a better approach. 

As said, there could be done many assumption on the firewall to find out, whether the traffic should be considered as IN or OUT. 

Do you know, how other vendor actually perform, if you create a ANY-ANY Rule? This will hit for internal and external Traffic, hence it will lead to weird traffic data counter, isnt it? Also rules, which implies LAN and external zone in it (LAN & WAN to LAN & WAN).  

Your examples makes perfectly sense, but are actually hard to archive and could lead to conflicts, which needs to be considered. 

PS: There are setups, which this will eventually break: XG without WAN Zone but Uplink to the Internet (eBGP, Upstream hosts etc.), Parent Proxy Setups. DNAT into a VPN Tunnel (Traffic coming from WAN, going into the VPN Tunnel. Is it Out, Out? Hard to tell). 

LuCar Toni 

the RX and TX are independent from the zone. RX and TX depends on the NIC where you are listening to.

For example:

your computer is sending a request to download data (it is not actually downloading the package) from an external public ip, what happens in terms of RX/TX?

your computer nic: high TX/low RX

nic of the switch where the computer is connected (ETH 0): high RX (because the port is receiving the request) / low TX

nic of the switch where the router is connected (ETH 23): high TX (because the same number of packets (with some modification) is sent / low RX

Now the package has been identified and the process starts again from the server high TX to router WAN port (high RX), high TX from router port to switch port ETH 23 (RX), ETH 0 TX and the computer nic RX.

This process applies in networking since 1960s.

Hope now it is clear.

It was clear in the beginning, but what are you suggesting? 

Are you see an issue in the way, XG is doing this? If you, please name it, maybe i can talk about this. 

RX/TX is just another phrase of IN/OUT (Interface/NIC Level). 

It was clear in the beginning, but what are you suggesting? 

Are you see an issue in the way, XG is doing this? If you, please name it, maybe i can talk about this. 

RX/TX is just another phrase of IN/OUT (Interface/NIC Level).